Burglar-alarm



Patented Mar. 25, 1890-.

D, mm

ulvLilhbgmphar. Washington. p. a

(No Model.)

A. ABRAHAM S. BURGLAR ALARM N PETERS. Ph

UNITED STATES PATENT ()FFICE.

ALBERT ABRAHAMS, OF EVANSVILLE, INDIANA.

BU RGLAR-ALARM.

SPECIFICATION forming part of Letters Patent No. 424,243, dated March 25, 1890.

Application filed December 3, 1889. Serial No. 332,434. (No model.)

To to whom it may concern:

Be it known that I, ALBERT ABRAHAMS, a citizen of the United States, residing at Evansville, in the county of Vanderburg and State of Indiana, have invented certain new and useful Improvements in Burglar- Alarms, of which the following is a specification, reference being had therein to the accompanying drawings, in which- Figure 1 represents a view of a portion of a door with my invention applied to it; Fig. 2, a sectional View of the door, showing the devices in side elevation; and Fig. 3, a view showing another method of using my devices on a door.

The invention has for its objects to produce an automatic burglar-alarm for employment on doors and windows, which shallbe exceedingly simple in construction and which will be perfectly reliable in operation, the mechanism being so arranged and constructed that the slightest turning of the door-knobs or movement of the. door will set in motion a continuous alarm, as, will more fully hereinafter appear.

I11 the annexed drawings, a designates a casing of suitable construction bolted to the door above the door-knob and containing clock-work mechanism of suitable construction to actuate the alarm mechanism. This clock-work is wound up whenever desired'by a thumb-piece Z). Connected to the arbor of the pallet-arm of the clock-work is a hammer cl, which strikes the gong e, secured on the door adjacent to the casing. The pallet-shaft c is provided with a horizontal arm f, depending from the outer end of which is a loose rod g, which, when the alarm is set, rests upon the shank of the door-knobs.

To prevent the alarm ringing while it is not set, I provide an angle-arm h and pivot the same in an aperture in the front plate of the casing, the horizontal arm of this lever extending into the casing under the arm f and its vertical arm being on the outside of the easing and extending downwardly and adapted to engage a hook ion the casing. \Vhen the outside arm of this locking-lever h is placed under the hook 2', the inner arm Will be held up under the arm fand prevent the pallet vibrating; but when this outside arm is dis engaged from its hook the pallet will be free to operate.

As described and shown, when the device is set the depending arm or rod g rests upon the shank of the door-knobs. As thus arranged it will be observed that the instant the knobs are turned in either direction this loose rod g will be thrown off the shank, thereby releasing the pallet-arm and perm tting it to sound the alarm-bell, which will ring continuously, unless stopped by the locking-arm, until the clock-work runs down.

In lieu of arranging the devices as above described, I may extend the armf out through the casing and secure the latter (and the bell) upon an adjacent portion of the doorframe. The arm f engages a notched or grooved plate j upon the door in such a manner that when the door is'opened the said arm will be pushed downward and released, as shown in Fig. 3.

It will be observed that the device may employed upon windows as well as doors.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is

1. 111 a burglar-alarm, the combination of a cl0ck work mechanism secured upon the door above the doorknob, a hammer, secured to the pallet-shaft thereof, a gong, a horizontal arm f, secured to the pallet shaft of the mechanism, and a depending rod g, loosely hung to the said arm f and adapted to rest upon the shank of'the door-knob, whereby the slightest rotation of the shank either way will displace the rod g and cause the alarm to ring, substantially as described.

2. The combination of a casing a, a clockwork mechanism located therein, ahammer secured to -the pallet-shaft thereof, a gong, an arm f, secured to the pallet-shaft of": the mechanism, a rod g, connected to said arm, an angle locking-lever 7L, pivoted in an ac ture in the casing, one arm of this lever extending into the casing below the arm f and the other arm extending outside of the easing, and a hook ion the casing for confining the outer arm of the angle-lever, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

ALBERT ABRAI-IAMS.

Witnesses:

SIM. DAY, T. E. CRUMBANAUGH. 

